The present invention relates to a rotary laser irradiating apparatus for forming a reference plane in civil engineering work such as ground leveling and a construction machine control system when construction machine is operated for civil engineering work. In particular, the invention relates to a construction machine control system utilizing a laser reference plane, which is formed by rotary irradiation of a laser beam in the work such as control of ground surface height in ground leveling operation.
When ground leveling operation is performed such as grounding leveling for housing development or for road paving using construction machines such as graders, bulldozers, etc., it is necessary to have a reference for height of the ground leveling. In recent years, a system using a laser beam has been propagated to determine the height, which serves as a reference in ground leveling operation. As a system using the laser beam, a construction machine control system equipped with a rotary laser irradiating apparatus has been proposed.
FIG. 8 shows a case where this construction machine control system is adopted for bulldozers.
In FIG. 8, reference numeral 1 represents a rotary laser irradiating apparatus, and 2 represents a bulldozer. The rotary laser irradiating apparatus 1 is installed via a tripod 3 at a predetermined position in a housing development area. The rotary laser irradiating apparatus 1 irradiates a laser beam 4 in a horizontal direction and also rotates the laser beam, and a reference plane is formed by the laser beam 4.
The bulldozer 2 has a blade 5, which is supported in such manner that it can be moved up or down. A pole 6 is erected on the blade 5, and a level sensor 7 is mounted on the pole 6. The level sensor 7 receives the laser beam 4 coming from the rotary laser irradiating apparatus 1 and detects a photodetecting position. The bulldozer 2 comprises a control unit (not shown), which detects height of the blade 5 based on a receiving signal from the level sensor 7 and controls height of the blade 5 based on the result of detection.
As described above, the horizontal reference plane is formed by the laser beam, and ground surface can be leveled in the horizontal direct-ion by maintaining the distance from the horizontal reference plane to a blade edge 5xe2x80x2 of the blade 5 at a constant value. By changing the distance to the blade edge 5xe2x80x2, the height of the ground surface to be leveled can be changed.
At a construction site of relatively small scale, construction work may be carried out by a single construction machine, while it is generally practiced to use many construction machines at the same time at a construction site. Further, the height of the ground surface to be leveled is usually different in each individual case when many construction machines are used for the construction. This means that a rotary laser irradiating apparatus is needed, which can set the levels for many construction machines at the same time. If a plurality of rotary laser irradiating apparatuses are used, erroneous operation of the construction machines may occur in receiving the laser beam.
In order to control a plurality of construction machines at the same time without causing erroneous operation, it is desirable to perform level setting by a single rotary laser irradiating apparatus. To perform level setting to each of the construction machines by a single rotary laser irradiating apparatus, it is necessary to perform level setting to each of the construction machines within one rotation of the laser beam. Conventionally, a laser beam is irradiated by rotary irradiation from an optical head, which is rotated at several hundreds of rpm in the rotary laser irradiating apparatus, and a reference plane or a reference line is formed. Therefore, a tilting mechanism is provided to tilt the optical head for level setting and tilt setting.
However, by the tilting mechanism, it is not possible to perform vertical adjustment at high speed as required in the level setting in two or more directions within one rotation of the laser beam, and a construction machine control system for controlling ground leveling operation with a plurality of construction machines by a single rotary laser irradiating apparatus is not yet developed for practical application.
Further, ground leveling operation is not only to level the ground to a horizontal surface, but an inclined ground surface may be prepared in many cases. In housing development construction, it is necessary to prepare a ground surface with such gradient as to be convenient for water drainage. In road paving construction, it is necessary to prepare a ground surface with the gradient to match topographical features and with the gradient suitable for water drainage. In the conventional type construction machine control system, a ground surface is leveled at first, and an inclined surface with a predetermined gradient is prepared according to the result of survey operation.
Although operators without special skill may be able to prepare a horizontal ground surface by the construction machine control system as described above, it is very difficult to prepare a ground surface with gradient, and this requires a skilled operator. Good finishing condition of the ground leveling in case of the inclined ground surface depends much upon the skill of the operator. The progress of the work varies according to the skill and the experience of the operator, and there are also problems of finishing and process control.
It is an object of the present invention to provide a system, by which level setting can be performed within a plurality of ranges during one rotation of the laser beam by a single rotary laser irradiating apparatus. It is another object of the invention to provide a system to control a plurality of construction machines by a single rotary laser irradiating apparatus. It is still another object of the invention to provide a system to perform ground leveling operation including preparation of inclined ground surface in easy and efficient manner and without being influenced by skill and experience of the operator.
The rotary laser irradiating apparatus according to the present invention comprises a laser source, a rotator for forming a laser reference plane by rotary irradiation of laser beam from the laser source, scanning means for deflecting the laser beam from the laser source, and control means for controlling the scanning means. Further, the present invention provides the rotary laser irradiating apparatus as described above, wherein there is further provided an encoder for detecting an irradiating direction of the rotator, and the control means controls the scanning means in such manner that the laser reference plane is formed at a predetermined position in a predetermined direction. Also, in the rotary laser irradiating apparatus of the present invention, the scanning means is provided on the rotator. The present invention provides the rotary laser irradiating apparatus as described above, wherein the system comprises an encoder for detecting an irradiating direction of the rotator, scanning means provided on an optical path between the laser source and the rotator and used for deflecting the laser beam, an image rotator provided on an optical path between the scanning means and the rotator and used for rotating the laser beam, and control means for controlling the scanning means in such manner that the laser reference plane is formed at a predetermined position in a predetermined direction, and the image rotator is integrally moved so that it is rotated by xc2xd turn of the rotator. Also, the present invention provides the rotary laser irradiating apparatus as described above, wherein there is provided a relay lens having a focal point on the rotator and the scanning means on an optical path between the image rotator and the rotator. Further, in the rotary laser irradiating apparatus of the present invention, the laser source is turned off in a predetermined direction based on the detection from the encoder. The present invention also provides a construction machine control system, which comprises a construction machine, a rotary laser irradiating apparatus for changeably forming a laser reference plane for position control of a ground leveling equipment of the construction machine, a GPS receiver for detecting a position of the construction machine, an equipment control means arranged on the construction machine and used for detecting the laser reference plane for controlling the position of the ground leveling equipment, and an arithmetic means for controlling the rotary laser irradiating apparatus in such manner that a laser reference plane corresponding to the position of the construction machine is formed based on detection result of the GPS receiver, and the system controls ground leveling operation of the construction machine. Also, the present invention provides the construction machine control system as described above, wherein the system comprises a GPS receiver provided on the construction machine, transmitting means for transmitting a result of receiving from the GPS receiver, a rotary laser irradiating apparatus for forming a laser reference plane corresponding to the position of the construction machine during one turn of rotation, a level sensor provided on the construction machine and for detecting the laser reference plane, equipment control means for controlling the position of the ground leveling equipment based on the detection result of the level sensor, receiving means for receiving transmission from the transmitting means, and an arithmetic means comprising a storage unit in which working data, topographical data, etc. are stored, for calculating a position of the construction machine based on information obtained from the receiving means, and controlling a laser beam irradiating direction from the rotary laser irradiating apparatus based on information stored in the storage unit. Further, in the construction machine control system of the present invention, the system comprises a GPS receiver provided on the construction machine, transmitting means for transmitting a result of receiving from the GPS receiver, a rotary laser irradiating apparatus for forming a laser reference plane corresponding to the position of the construction machine by using a plurality of laser rotation by on-off control of the laser beam, a level sensor provided on the construction machine and for detecting the laser reference plane, equipment control means for controlling the position of the ground leveling equipment based on the detection result of the level sensor, receiving means for receiving transmission from the transmitting means, and an arithmetic means comprising a storage unit in which working data, topographical data, etc. are stored, for calculating a position of the construction machine from information obtained from the receiving means, and controlling a laser beam irradiating direction from the rotary laser irradiating apparatus according to information stored in the storage unit. Also, the present invention provides the construction machine control system as described above, wherein the GPS receiver comprises a first GPS receiver and a second GPS receiver, the GPS receiver is provided on a construction machine and the second GPS receiver is positioned at a known point. Further, the present invention provides the construction machine control system as described above, wherein there is a plurality of construction machines.